Ester Additive and Over-Blown Paving Asphalt for Roofing
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Solution Overview
Problem
Conventional methods for producing Built Up Roofing Asphalt (BURA) compositions from paving grade asphalt are inadequate, as they require costly processing modifications and the use of scarce and expensive coating-grade asphalts, limiting the availability and increasing the cost of shingle production.
Innovation Solution
The process involves over-blowing paving grade asphalt to achieve a higher softening point, followed by the addition of a modified vegetable oil or ester additive to adjust the penetration and softening point within the desired range for BURA, allowing for the use of existing processing lines without significant capital expenditures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If coating grade asphalt is used as feedstock for air blowing process, then the desired BURA properties are achieved, but the supply security deteriorates and cost increases
Solution Approach 1:
The invention changes the feedstock parameter from coating grade asphalt to paving grade asphalt, and adjusts the air blowing process parameters (time, temperature, air flow rate) to transform the hard asphalt into a composition with desired BURA properties. This parameter substitution resolves the supply security issue while maintaining product quality.
Solution Approach 2:
The invention discards the conventional requirement for scarce coating grade asphalt and recovers/utilizes the abundant paving grade asphalt instead. By applying air blowing treatment to paving grade asphalt, the process recovers the desired roofing performance properties from an alternative feedstock source.
2Manufacturing precision
If coating grade asphalt is used as feedstock for air blowing process, then the desired BURA properties are achieved, but the manufacturing cost increases
Solution Approach 1:
The invention changes the feedstock parameter from expensive coating grade asphalt to cheaper paving grade asphalt. The extended air blowing process parameters compensate for the harder nature of paving asphalt, achieving the same BURA properties at lower material cost.
3Quantity of substance
If paving grade asphalt is used directly without modification, then the cost decreases and supply security improves, but the BURA properties are inadequate
Solution Approach 1:
The invention applies parameter changes to the air blowing process (increased time, adjusted temperature, modified air flow rate) to transform paving grade asphalt with inadequate properties into a composition meeting BURA specifications. This maintains supply security while achieving required performance.
Solution Approach 2:
The air blowing process performs preliminary oxidation and modification of the paving grade asphalt before it is used in BURA production. This preliminary treatment adjusts the asphalt's physical properties to meet roofing application requirements.
4Stability of the object's composition
If paving grade asphalt is over-blown to achieve desired softening point, then the thermal stability improves, but the processing time increases
Solution Approach 1:
The invention optimizes the air blowing parameters (temperature, air flow rate, blending time) to achieve the minimum necessary thermal stability. By carefully controlling these parameters, the process achieves adequate softening point elevation without excessive processing time extension.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables the production of thermally stable BURA compositions that meet the required properties for roofing applications, maintaining stability at high processing temperatures and reducing manufacturing costs by utilizing a broader range of asphalt feedstocks.
Implementation Method 1
air blowing, which is an oxidation process that involves blowing air through molten asphalt to modify the physical properties of the asphalt
Implementation Method 2
the addition of a modified vegetable oil or ester additive to adjust the penetration and softening point within the desired range for BURA
Data Source
AI summary
Thermally stable built-up roofing asphalt (“BURA”) composition comprising a paving grade asphalt is disclosed. The paving grade asphalt has been over-blown to a first softening point and an additive is included in an amount to achieve a second softening point. The additive comprises at least at least one ester. The BURA composition is thermally stable at processing temperatures of at least 450° F.